Non-cleavable polymer conjugated with alpha V beta 3 integrin thyroid antagonists

ABSTRACT

Chemical compositions and methods of synthesis thereof. The compositions disclosed and described herein are directed toward and classified as anti-angiogenic thyrointegrin antagonists, which may be capable of reacting with one or more cell surface receptors of the integrin αvβ3 receptor family. Anti-angiogenic thyrointegrin antagonists or derivatives thereof are conjugated via a non-cleavable linker having an amine, diamine or triazole linkage to polymers of Polyethylene Glycol, cyclodextrin, chitosan, alginic acid or hyaluronic acid, forming a single chemical entity. Utility of the compositions disclosed may treat angiogenesis-mediated disorders such as Cancer (Solid tumors and Liquid tumors), ocular disorders (Diabetic Retinopathy and Age-related Macular Degeneration), inflammatory disorders (arthritis, osteoarthritis), atherosclerosis, lesions, and dermatology (Rosacea, Psoriasis, skin cancer) and diseases mediated or dependent upon the generation of new blood cells via angiogenesis to persist and the treatment thereof or dependent on antagonizing the formation of new blood vessels to slow or eliminate angiogenic pathways.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority and benefit of U.S. patent application Ser. No. 15/616,637 entitled “NON-CLEAVABLE POLYMER CONJUGATED WITH ALPHA V BETA 3 INTEGRIN THYROID ANTAGONISTS” filed on Jun. 7, 2017 and U.S. Patent Application No. 62/346,659 entitled “NOVEL COMPOSITIONS AND METHODS OF US OF NON-CLEAVABLE POLYMER CONJUGATED WITH NOVEL ALPHA-V-BETA-3 THYROID ANTAGONISTS, filed Jun. 7, 2016, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates generally to thyroid hormone receptor antagonists (referred to as “thyrointegrin antagonists”) and more specifically to alpha-V-beta-3 (αvβ3) integrin-thyroid hormone receptor antagonists conjugated via a non-cleavable bond of a linker with or without a short chain of PEG to one or more polymers (in embodiments utilizing a polymer other than PEG).

BACKGROUND

Integrins are a super-family of cell surface adhesion receptors, which control the attachment of cells with the solid extracellular environment, both to the extracellular matrix (ECM), and to other cells. Adhesion is of fundamental importance to a cell; it provides anchorage, cues for migration, and signals for growth and differentiation. Integrins are directly involved in numerous normal and pathological conditions, and as such are primary targets for therapeutic intervention. Integrins are integral transmembrane proteins, heterodimers, whose binding specificity depends on which of the 14 α-chains are combined with which of the 8 β-chains. The integrins are classified in four overlapping subfamilies, containing the β1, β2, β3 or αv chains. A cell may express several different integrins from each subfamily. In the last several decades, it has been shown that integrins are major receptors involved in cell adhesion, and so may be a suitable target for therapeutic intervention. Integrin αvβ3 regulates cell growth and survival, since ligation of this receptor can, under some circumstances, induce apoptosis in tumor cells. Disruption of cell adhesion with anti-αvβ3 antibodies, RGD peptides, and other integrin antagonists has been shown to slow tumor growth.

SUMMARY

A first embodiment of this disclosure relates generally to a composition comprising a general formula:

wherein R1, R2, R3 and R4 are each independently selected from the group consisting of hydrogen, iodine, linear alkanes and branched alkanes; X is oxygen (O) or sulfur (S); n1≥0; Y is a non-cleavable covalent bond; and Z is a non-biodegradable polymer. Y=

Wherein n₅=1-5, and A=CH or N, with at least one A=N

A second embodiment of the present disclosure relates generally to a composition comprising a general formula:

wherein R¹, R², R³ and R⁴ are each independently selected from the group consisting of hydrogen, iodine, linear alkanes and branched alkanes; X is oxygen (O) or sulfur (S); n₁≥0; n₂>1; and Y=

A third embodiment of the present disclosure relates generally to a composition comprising a thyroid antagonist, a non-biodegradable polymer; and a linker covalently bound to the thyroid antagonist and the non-biodegradable polymer via a non-cleavable covalent bond. Wherein, even under some circumstances that one or more of the listed polymers may be cleaved through the use of harsh environmental conditions, a residual polymer chain may still be covalently bonded to the linker and MAT, DAT or TAT, capable of still restricting the cellular nucleus uptake of the conjugated thyroid antagonist.

BRIEF DESCRIPTION OF THE DRAWINGS

Some of the embodiments will be described in detail with references made to the following figures, wherein like designations denote like members, wherein:

FIG. 1 depicts an embodiment of a general chemical formula describing a thyroid antagonist and derivatives thereof.

FIG. 2a depicts an embodiment of a tetraiodothyroacetic acid (tetrac) derivative, monamino propyl tetrac (MAT).

FIG. 2b depicts an embodiment of a tetrac derivative, diamino propyl tetrac (DAT).

FIG. 2c depicts an embodiment of a tetrac derivative, propargyl tetrac (PGT).

FIG. 2d depicts an alternative embodiment of the tetrac derivative of FIG. 2 a.

FIG. 2e depicts an alternative embodiment of the tetrac derivative of FIG. 2 b.

FIG. 2f depicts an alternative embodiment of the tetrac derivative of FIG. 2 c.

FIG. 3a depicts an embodiment of a triiodothyroacetic acid (triac) derivative, monoamino propyl triac (MATri).

FIG. 3b depicts an embodiment of a triac derivative, diamino propyl triac (DATri).

FIG. 3c depicts an embodiment of a triac derivative, propargyl triac (PGTri).

FIG. 4a depicts an embodiment of a thyrointegrin antagonist derivative.

FIG. 4b depicts an alternative embodiment of a thryointegrin receptor antagonist derivative.

FIG. 4c depicts another alternative embodiment of thyrointegrin antagonist derivative.

FIG. 5 depicts an embodiment of general chemical formula describing a thyroid hormone antagonist derivative conjugated to a polymer via a non-cleavable bond.

FIG. 6 depicts an embodiment of a general formula of a thyroid hormone antagonist derivative conjugated via a non-cleavable bond to a polyethylene glycol (PEG) polymer.

FIG. 7a depicts an embodiment of a thyroid hormone antagonist conjugated to a PEG polymer via a non-cleavable monoamino bond forming PEG-monoamino propyl tetrac (P-MAT).

FIG. 7b depict an embodiment of a thyroid hormone antagonist conjugated to a PEG polymer via a non-cleavable diamino bond forming PEG-diamino propyl tetrac (P-DAT).

FIG. 7c depict an embodiment of a thyroid hormone antagonist conjugated to a PEG polymer via a non-cleavable N—C bond forming PEG-triazole tetrac (P-TAT).

FIG. 8 depicts embodiments of conjugation routes for synthesizing αvβ3 thyroid hormone antagonists via cleavable and non-cleavable linkers using methoxy-polyethylene glycol (mPEG).

FIG. 9 depicts an embodiment of a general formula of a bifunctional thyrointegrin antagonist derivative comprising two conjugations via a non-cleavable bond to a PEG polymer.

FIG. 10a depicts an embodiment of a bifunctional thyrointegrin antagonist derivative, polyethylene glycol bi-monoamino propyl tetrac (P-bi-MAT).

FIG. 10b depicts an embodiment of a bifunctional thyrointegrin antagonist derivative, polyethylene glycol bi-diamino propyl tetrac (P-bi-DAT).

FIG. 10c depicts an embodiment of a bifunctional thyrointegrin antagonist derivative, polyethylene glycol bi-triazole tetrac (P-bi-TAT).

FIG. 11 depicts an embodiment of methods for synthesizing P-bi-MAT, P-bi-DAT and P-bi-TAT.

FIG. 12 depicts an embodiment of methods for synthesizing tetra functional derivatives of thyrointegrin antagonists, polyethylene glycol tetra-monoamino propyl tetrac (P-tetra-MAT (P-tetra-MAT), polyethylene glycol tetra-diamino propyl tetrac (P-tetra-DAT) and polyethylene glycol tetra-triazole tetrac (P-tetra-TAT) using tetra polyethylene glycol.

FIG. 13a depicts an embodiment of a general formula of a thyrointegrin antagonist derivative conjugated to a cyclodextrin.

FIG. 13b depicts an embodiment of a chemical structure for cyclodextrin monoamino propyl tetrac (C-MAT).

FIG. 13c depicts an embodiment of a chemical structure for cyclodextrin diamino propyl tetrac (C-DAT).

FIG. 13d depicts an embodiment of chemical structure for cyclodextrin triazole tetrac (C-TAT).

FIG. 14a depicts an embodiment of a method for synthesizing C-MAT and C-DAT using an alpha (α), beta (β) or gamma (γ) cyclodextrin.

FIG. 14b depicts an embodiment of a method for synthesizing C-TAT using an alpha (α), beta (β) or gamma (γ) cyclodextrin.

FIG. 15a depicts an embodiment of a thyrointegrin antagonist derivative conjugated to an alginic acid polymer forming alginic acid monoamino propyl tetrac (A-MAT).

FIG. 15b depicts an embodiment of a thyrointegrin antagonist derivative conjugated to an alginic acid polymer forming alginic acid diamino propyl tetrac (A-DAT).

FIG. 15c depicts an embodiment of a thyrointegrin antagonist derivative conjugated to an alginic acid polymer forming alginic acid triazole tetrac (A-TAT).

FIG. 16a depicts an embodiment of a method for synthesizing A-MAT and A-DAT from alginic acid.

FIG. 16b depicts an embodiment of a method for synthesizing A-TAT from Alginic acid.

FIG. 17a depicts an embodiment of a thyrointegrin antagonist derivatives conjugated to a hyaluronic acid polymer with a non-cleavable monoamino bond forming hyaluronic acid-monoamino propyl tetrac (H-MAT).

FIG. 17b depicts an embodiment of a thyrointegrin antagonist derivatives conjugated to a hyaluronic acid polymer with a non-cleavable diamino bond forming hyaluronic acid-diamino propyl tetrac (H-DAT).

FIG. 17c depicts an embodiment of a thyrointegrin antagonist derivatives conjugated to a hyaluronic acid polymer with a non-cleavable triazole bond forming hyaluronic acid-triazole propyl tetrac (H-TAT).

FIG. 18a depicts an embodiment of a method for synthesizing H-MAT and H-DAT from hyaluronic acid.

FIG. 18b depicts an embodiment of a method for synthesizing H-TAT from hyaluronic acid.

FIG. 19 depicts an embodiment of a method for synthesizing a thyrointegrin antagonist having a linker comprising a propargyl group.

FIG. 20 depicts an embodiment of a method for synthesizing propargylated tetrac (PGT).

FIG. 21 depicts the effect of P-bi-TAT on Matrigel growth factors implant-mediated angiogenesis in mice and a dose-dependent anti-angiogenesis efficacy for P-bi-TAT in mouse Matrigel growth factor-mediated angiogenesis.

FIG. 22 depicts the effects of P-bi-TAT (1 mg/Kg, SC QD for 14 days) on ovarian (OVCAR3)-tumor angiogenesis in nude mice.

FIG. 23 depicts the expression of αvβ3 protein by flow cytometry.

FIG. 24a-24d depicts the expression of αvβ3 protein in GBM cells using confocal microscopy.

FIG. 25 depicts polymer conjugated DAT decreased bioluminescent signals of THP1-luc cells in the bone marrow and liver metastasis of transgenic mice with Acute Myeloid Leukemia (AML).

FIG. 26 depicts Bioluminescent signals of the tumors GBM xenografts (21 days on treatment termination), the average bioluminescent signal intensity of the control and void being 2-3×10⁷ photons/sec and the treated groups (1 mg/kg and 3 mg/kg) having a bioluminescent signal intensity of <1-2×10⁴ photons/sec.

FIG. 27 depicts bioluminescent signals of the tumors GBM xenografts (21 days and 22 days off treatment termination), the average bioluminescent signal intensity of the control and void being 2-3×10⁷ photons/sec and the treated groups (1 mg/kg and 3 mg/kg) having a bioluminescent signal intensity of <1-2×10⁴ photons/sec.

FIG. 28 depicts the effect of polymer Conjugated DAT or TAT on GBM tumor growth in nude mice xenografts after 21 days of daily treatment at 1 and 3 mg/Kg DAT or TAT equivalent (Days ON treatment) and in another arm of 21 days ON followed by 22 Days OFF treatment.

FIG. 29 depicts the effects polymer Conjugated C-TAT and P-bi-TAT on GBM tumor growth in nude mice xenografts after 21 days of daily treatment at 1 and 3 mg/Kg DAT or TAT equivalent (Days ON treatment) and in another arm of 21 Days ON followed by 22 Days OFF treatment.

FIG. 30 depicts the effects of polymer conjugated P-bi-TAT on GBM tumor growth in nude mice xenografts after 21 days of daily treatment at 3 and 10 mg/kg, subcutaneously (SC) daily (1 and 3 mg/Kg TAT equivalent, respectively) (Days ON treatment) and in another arm of 21 Days ON followed by 22 Days OFF treatment.

FIG. 31 depicts the loss of tumor cell viability induced by P-bi-TAT in GBM U87MG mouse xenografts. P-bi-TAT (3 mg/kg) and P-bi-TAT (10 mg/kg) are, respectively, daily drug dosages at 3 and 10 mg P-bi-TAT/kg s.c., for 21 days, achieving reductions in cell viability of 62% and 72% (based on histological score). Error bars represent standard error of the mean (S.E.M.).

FIG. 32 depicts bioluminescent signals of GBM U87MG-luc mouse xenografts, 21-days ON treatment OR 21-days ON treatment and 22-days OFF treatment before termination. Average bioluminescent signal intensity in control was 2-3×10⁷ photons/sec. In the treated groups, signal intensity was <1-2×104 photons/sec (limit of detection). In these IVIS images, the vertical luminescence color bar (left margin) estimates viability, ranging from nonviable (0 p/sec/cm²/sr) to fully viable (6 p/sec/cm²/sr).

FIG. 33 depicts Cy5 signals in the orthotropic brain (GBM) tumors in vivo at 30 minutes and 4 hours post-administration of P-bi-TAT and other polymer conjugated TAT compositions (upper images). Lower Images illustrate the image intensity for CY5 P-bi-TAT and other polymer conjugated TAT in orthotopic brain GBM tumor and subcutaneous xenograft GBM tumor.

FIG. 34 depicts a graph of an embodiment of the kinetics of CY5 signal intensity of P-bi-TAT in GBM brain tumors.

FIG. 35 depicts a graph of an embodiment of the kinetics of CY5 signal intensity of P-bi-TAT in subcutaneous xenograft GBM tumors.

FIG. 36 depicts an embodiment of a graph describing Cy5 Labeled P-bi-TAT signal intensity in brain and subcutaneous GBM tumors removed at the end of the study (4 hours).

FIG. 37 depicts bioluminescent signals of GBM (U87-luc) orthotropic tumors in brain of a control versus P-bi-TAT treated animals at 1, 3 and 10 mg/kg, SC daily for 7 days.

FIG. 38 depicts a graph describing the effects of P-bi-TAT and NTAT (Polymer Conjugated TAT at 1 mg/kg, SC daily for 7 days) on bioluminescent signals of GBM (U87-luc) in the brain.

FIG. 39 depicts a graph describing the results of the effect of P-bi-TAT on GBM subcutaneous tumor growth after one-week treatment.

FIG. 40 depicts a graph describing the dosing effects of P-bi-TAT on GBM tumor viability using IVIS imaging.

FIG. 41a depicts a graph of the anticancer efficacy of P-bi-TAT on pancreatic cancer, SUIT 2, at 3 mg/kg and 10 mg/kg compared with a control as a function of tumor weight.

FIG. 41b depicts a graph of the anticancer efficacy of P-bi-TAT on pancreatic cancer, SUIT 2, at 3 mg/kg and 10 mg/kg compared with a control as a function of cell viability.

FIG. 41c depicts a graph of the anticancer efficacy of P-bi-TAT on pancreatic cancer, SUIT 2, at 3 mg/kg and 10 mg/kg compared with a control as a function of % cell necrosis.

FIG. 42a depicts a graph describing the effects of radiation/non-radiation exposure alone (PBS), and radiation or none/radiation exposure in conjunction with dosages of P-bi-TAT (3 mg/kg and 10 mg/kg) on pancreatic cancer SUIT 2, the effects being described as a function of xenograft tumor weight.

FIG. 42b depicts a graph describing the effects of radiation/non-radiation exposure alone (PBS), and radiation or none/radiation exposure in conjunction with dosages of P-bi-TAT (3 mg/kg and 10 mg/kg) on pancreatic cancer SUIT 2, the effects being described as a function of % cell viability.

FIG. 42c depicts a graph describing the effects of radiation/none-radiation exposure alone (PBS), and radiation or none/radiation exposure in conjunction with dosages of P-bi-TAT (3 mg/kg and 10 mg/kg) on pancreatic cancer SUIT 2, the effects being described as a function of % cell necrosis.

FIG. 43 depicts a graph describing the effects of radiation exposure alone and radiation exposure in conjunction with dosages of P-bi-TAT on pancreatic cancer SUIT 2 at 1GY and 5GYs of radiation with the results depicted as a function of xenograft tumor weight.

FIG. 44 depicts graphs describing Levels of hepatic, cardiac and renal markers in plasma of male and female mice treated with P-bi-TAT. Measurements in murine plasma of markers of liver damage (aspartate transaminase (AST) and alanine transaminase (ALT)), myocardial damage (cardiac troponin I (cTnI)) and renal function (creatinine) in mice treated daily for 14 days subcutaneously with P-bi-TAT in the concentrations (ng/mL) shown. Error bars represent standard error of the mean (S.E.M.).

FIG. 45 depicts an embodiment of a method for synthesizing a cyclodextrin conjugated thyrointegrin antagonist C-TAT.

DETAILED DESCRIPTION

A detailed description of the hereinafter-described embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference made to the Figures. Although certain embodiments are shown and described in detail, it should be understood that various changes and modifications might be made without departing from the scope of the appended claims. The scope of the present disclosure will in no way be limited to the number of constituting components, the materials thereof, the shapes thereof, colors thereof, the relative arrangement thereof, etc., and are disclosed simply as an example of embodiments of the present disclosure. A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features.

As a preface to the detailed description, it should be noted that, as used in this specification and the appended claims, the singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.

Overview

Embodiments of the present disclosure describe new chemical compositions, and methods of synthesis thereof. The compositions disclosed and described herein may be directed toward and classified as anti-angiogenic agents, which may be capable of reacting with one or more cell surface receptors of the integrin αvβ3 receptor family. The compositions described herein may include an anti-angiogenic thyroid hormone or derivative thereof conjugated via a non-cleavable linker to a polymer, forming a single chemical entity which may considered a micro molecule or macromolecule (depending on the size of the polymer covalently bound to the thyroid hormone or derivative thereof). The size of the single chemical entity and the strength of the non-cleavable covalent bond may be advantageous for preventing the thyroid hormone or derivative thereof from entering cells comprising a cell surface receptor of the integrin αvβ3 variety. Due to the size of the attached polymer, and the inability of the surrounding environment of the cell to cleave the strong, uncleavable covalent bonds of the thyroid hormone from the polymer, the thyroid hormone portion of the described chemical entities may be unable to be internalized within the nucleus of the cells which the thyroid hormone or derivative thereof may interact. Accordingly, the thyroid hormone portion of the described chemical entities may interact with the cells non-genomically and avoid genomic interactions that may be caused by thyroid hormones or derivatives thereof entering a cell and interacting with the nuclear receptors of the cellular nucleus.

Embodiments of the compositions disclosed herein may be synthesized to include, but are not limited to entities comprising non-biodegradable polymers such as polyethylene glycol (PEG) (1,000-15,000 Daltons, for example between 4,000-8,000 Daltons), α, β, or γcyclodextrins, chitosan, alginic acid or hyaluronic acid, conjugated via non-cleavable linker comprising an amine or triazole bond, without short chain of PEG (100-800 M.W.) to an αvβ3 thyroid antagonist. Embodiments of the thyroid antagonists conjugated to the polymers may include tetraiodothyroacetic acid (tetrac), triiodothyroacetic acid (triac), derivatives thereof and variations thereof. Examples of one or more variations of the thyroid hormone antagonists comprising tetrac and triac may include, in some embodiments Diaminotetrac (DAT) or Diamnotriac (DATri) (hereinafter may be referred to interchangeably as “DAT”), Monoaminotetrac (MAT) or Monoaminotriac (MATri) (hereinafter referred to interchangeable as “MAT”), Triazoletetrac (TAT) or Triazoletriac (TATri) (hereinafter referred to interchangeable as “TAT”), derivatives thereof or other thyroid antagonist known by those skilled in the art.

Embodiments of the compositions described herein have been further synthesized and characterized as DAT, MAT or TAT conjugated to different molecular weights of Polyethylene Glycol (1,000 to 15,000 Dalton). We have scaled up embodiments of the relatively most soluble, PEG-DAT (P-Mono-DAT, P-bi-DAT) and PEG-TAT (P-Mono-TAT, P-bi-TAT), for biological characterization in various in vitro and in vivo biological systems. Chemical labelling of DAT or TAT and PEG-DAT or PEG-TAT as well as C-DAT and C-TAT for imaging and cellular kinetics. Data revealed that polymer conjugation to DAT or TAT resulted in the restriction of cell nuclear uptake of those polymers conjugated DAT or TAT versus intense cell nuclear uptake of DAT or TAT. The result of this unique cellular distribution lead to the lack of genomic action of the polymer conjugated DAT, MAT or TAT versus the non-conjugated ones. Other Polymers such as Hyaluronic, Alginic acid, Chitosan conjugated to DAT, MAT or TAT with or without short chain short chain PEG (100-1,000 Dalton) are described. Additional Polymer conjugation to DAT, MAT or TAT were synthesized using bi-functional or tetra-function PEG may include, but it could also include other branched PEG up to 8 chains.

Embodiments of each of the compounds described in the current application may multiple types of utility for treating a plurality of different diseases modulated by angiogenesis or the inhibition thereof. Each of the compositions described in the present disclosure, in view of presence of the thyroid antagonist present in the described compositions, may each have an affinity for targeting the integrin receptor αvβ3 located on numerous types of cells found throughout the human body and various animal bodies.

For example, the utility of the compositions disclosed herein may be useful for treating angiogenesis-mediated disorders such as Cancer (Solid tumors and Liquid tumors) in humans or mammals. Cancers may include Glioblastoma, pancreatic, ovarian, breast, prostate, bladder, lung and liver cancer. Liquid tumors may also acute myeloid leukemia, multiple myeloma, Lymphoma and chronic lymphocytic leukemia. The compositions described herein may further treat ocular disorders (Diabetic Retinopathy and Age-related Macular Degeneration), inflammatory disorders (arthritis, osteoarthritis), atherosclerosis lesions, and dermatology (Rosacea, Psoriasis, skin cancer) which may each be mediated or dependent upon the generation of new blood cells via angiogenesis to persist and the treatment thereof may be dependent antagonizing the formation of new blood vessel to slow or eliminate the angiogenic pathways.

While embodiments and examples of the present disclosure described herein, for purposes of illustration, modifications and changes will become apparent to those skilled in the art based on the examples illustrated. Accordingly, the appended examples intended to encompass all variations and such modifications and changes that fall within the true spirit and scope of this disclosure.

Thyrointegrin Antagonist Compositions

Referring to the drawings, FIG. 1 depicts an embodiment of a general formula 100 describing a thyroid hormone antagonist attached to a linker comprising a repeating linkage of carbon atoms which may be defined by n₁ carbon subunits and “Y” which may define a non-cleavable covalent bond attached to the linker of the thyroid hormone antagonist and derivatives thereof of the general formula 100. The term “thyroid hormone antagonist” may describe the ability of a molecule of general formula 100 to inhibit or antagonize one or more thyroid hormone receptors known by a person skilled in the art, for example the integrin family of thyroid hormone receptors, such as the thyroid hormone cell surface receptor αvβ3. Due to the functionality of the thyroid hormone antagonist and derivatives thereof to inhibit integrin receptors, the molecule defined by the general formula 100 may further be described herein as a thyrointegrin antagonist.

As shown by the chemical structure of the general formula 100 of FIG. 1, embodiments of the chemical structure may include one or more variables defining the additional features of the thyrointegrin antagonist of FIG. 1. For example, in some embodiments of the thyrointegrin antagonist, the variables depicted as R¹, R², R³ and R⁴ may be each independently be substituted for molecules of hydrogen, iodine, linear alkanes, branched alkanes and cyclic alkanes. In some embodiments, the variable “X” may be defined as an oxygen atom (O) or a sulfur atom (S).

Embodiments of the carbon linker connected to the thyroid antagonist of the general formula 100 may be variable in the length of the carbon chain. The length of the carbon chain may be as small as one carbon atom between oxygen molecule and the non-cleavable covalent bond “Y”. In alternative embodiments of the thyrointegrin antagonist, the linker may comprise repeating links of carbon atoms, which may be defined by n₁ repeats. n₁ may be ≥0 in some embodiments, while in alternative embodiments of the general formula 100, the repeating number of carbon atoms in the linker of n₁ may be ≥0, ≥1, ≥2 or ≥3.

Embodiments of the non-cleavable covalent bond, depicted by the variable “Y”, may in some instances be may be an amine bond. For example, the variable Y of the general formula may be a monoamine having one amine group or a diamine having two amine groups in the non-cleavable covalent bond as shown by the examples of thyrointegrin antagonists 210, 215, 220, 225, 310, 320, 410, 420 of FIGS. 2a-2b, 2d-2e, 3a-3b, 4a-4b . In alternative embodiments, the substituted variable Y may include a propargyl group as shown in shown in FIGS. 2c, 2f, 3c and 4 c.

As demonstrated by the embodiments of FIG. 2a-4c , there is a wide range of derivative compositions that may be formed from the general formula 100. For example, in FIG. 2a , the composition 210 may comprise a substitution of iodine for R¹-R⁴, resulting in the formation of a tetraiodothyroacetic acid (tetrac) derivative having a three-carbon linker and a monoamine as the non-cleavable covalent bond. Composition 210 may be referred to as monoamine-tetrac (MAT). Likewise, in FIG. 2b , the tetrac molecule further comprises a diamino covalent bond connected to the linker. Likewise, this composition 220 may be referred to a diamino tetrac (DAT). In the alternative embodiment of FIG. 2c , the composition 230 may comprise a propargyl group attached to a one-carbon linkage between the tetrac molecule and propargyl group as shown. This derivative composition 230 may be referred to as propargyl tetrac (PGT).

Synthesis of Propargylated Tetrac (PGT) from Tetrac

The following example provides a sample method for preparing propargyl tetrac or a derivative thereof from tetrac in accordance with the general chemical formula described in FIG. 19 and more specifically as applied to tetrac as shown in the synthesis diagram of FIG. 20.

Step 1: Esterification

Table 1a provides the synthesis conditions for esterifying tetrac into O-methyl tetrac (MR-2) (methyl-2-(4-(4-hydroxy-3, 5-diiodophenoxy)-3, 5-diiodophenyl) acetate):

Batch Input Output Purity by HPLC No. (g) (g) Reagents Yield (%) (% a/a) 01 10 9.3 SOCl₂ (2.5 eq.), 92 98.67 MeOH (37.5 vol.) 02 10 9.5 SOCl₂ (2.5 eq.), 94 ¹H NMR MeOH (25 vol.) recorded and compared 03 200 194 SOCl₂ (2.5 eq.), 95 99.15 MeOH (25 vol.)

In one embodiment for synthesizing MR-2, the composition is synthesized according to the protecting method previously published. A solution of tetraiodothyroacetic acid (1 g, 1.33 mmol, 1 equiv.) and boron tri-fluoride diethyl ether (BF₃.Et₂O) (0.1 mL) in methanol (10 mL) stirred under nitrogen at ambient temperature for 24 hours. Reaction quenched by adding 15 ml saturated aqueous NaHCO₃ solution and mixture stirred for 10 minutes, and the aqueous phase extracted with ethyl acetate (3×20 mL). The combined organic phases were dried with sodium sulfate, filtered, and concentrated under vacuum to afford 950 mg crude methyl-2-(4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl)acetate 2, which was then recrystallized by ethanol to give pure compound (630 mg, 0.82 mmol) with 62% yield. Recrystallization solvent: EtOH; R_(f): 0.62 with TLC solvent (n-Hexane: EtOAc/8:2); mp=162-4° C.; FTIR (ν cm⁻¹): 3371, 3082, 2943, 1719 cm⁻¹ (C═O), 1586, 1556, 1539, 1455, 1430, 1397, 1283, 1240, 1220, 1160, 1238, 912, 847, 823, 782, 700, 597, 527. ¹H NMR (CDCl₃) δ (ppm): 7.78 (s, 2H, ArH), 7.12 (s, 2H, ArH), 5.53 (br, 1H, OH), 3.75 (s, 3H, —COOCH₃), 3.58 (s, 2H, —CH₂—COO); ¹³C NMR (CDCl₃) δ (ppm): 171.0 (—COOMe), 152.8, 150.2, 149.6, 141.3, 135.2, 126.1, 90.9, 81.8, 52.7 (—COOCH₃), 39.8 (—CH₂—COO). MS (ESI⁺) m/z: 785 [M+Na]⁺; (ESP) m/z: 761 [M-H]⁻.

Step 2: Alkylation

TABLE 1B Synthesis Conditions for MR-3 (methyl {4-[3, 5-diiodo-4-(prop-2-yn- 1-yloxy) phenoxy]-3, 5-diiodophenyl} acetate) Batch. No. Temp (NNA-P-16- Input Output °C./Time Yield Purity by Impurity 01-II-XX) (g) (g) Reagents h (%) HPLC(%a/a) 1.02 RRT 04 10.0 8.6 g 80% Propargyl 55-60/24 82.7 71.12 27.41 bromide (3.0 eq.), K₂CO₃ (5.0 eq.) 08 10.0 9.4 80% Propargyl 55-60/1 89.5 97.7 1.12 bromide (3.0 eq.), K₂CO₃ (5.0 eq.) 09 1.0 0.94 80% Propargyl 25-35/1.5 90 94.72 4.19 bromide (3.0 eq.), K₂CO₃ (5.0 eq.) 12 1.0 0.94 80% Propargyl 25-35/1.5 90.38 96.61 0.8 bromide (1.0 eq.), K₂CO₃ (5.0 eq.) 13 1.0 0.71 80% Propargyl 0-5/1.5 68.12 98.53 0.28 bromide (1.0 eq.), K₂CO₃ (5.0 eq.) 14 30 25 80% Propargyl 0-5/12 79.13 96.97 N/A bromide (1.0 eq.), K₂CO₃ (5.0 eq.) 15 70 67 80% Propargyl 0-5/72 91.1 97.32 0.31 bromide (1.0 eq.), K₂CO₃ (5.0 eq.) 16 70 67 80% Propargyl 0-5/120 91.1 98.96 N/A bromide (1.0 eq.), K₂CO₃ (5.0 eq.)

In one embodiment, the step of alkylation may be performed A mixture of methyl-protected tetrac (1 eq) and propargyl bromide (3 eq) and potassium carbonate (5 eq) in 25 ml acetone was heated at reflux for 24 hours. The reaction was filtered, concentrated, and then crude purified with flash column chromatography over silica gel using n-hexane and ethyl acetate (9:1 to 7:3) to give methyl {4-[3,5-diiodo-4-(prop-2-yn-1-yloxy)phenoxy]-3,5-diiodophenyl}acetate with 78-85% yield. ¹H NMR (CDCl₃) δ (ppm): 7.76 (s, 2H, ArH), 7.16 (s, 2H, ArH), 4.6 (br, 1H, OH), 3.75 (s, 3H, —COOCH₃), 3.56 (s, 2H, —CH₂—COO); 2.54 (s, 2H, —O—CH₂—C—CH).

Step 3: Hydrolysis

TABLE 1C Synthesis Conditions for MR-4 {4-[3, 5-diiodo-4-(prop-2-yn-1-yloxy) phenoxy]-3, 5-diiodophenyl} acetic acid Input Output Yield Purity by Comments NNB- (g) (g) Reagents (%) HPLC(%a/a) 07 1.0 0.76 2M KOH (60 77 72.47 familiarization 10 1.0 0.71 vol.), 1:1 74 95.66 SM ester and ether of tetrac 17 65 62.1 Methanol: 97 97.9 Input material (MR-3) purity THF (60 vol.), 97.3% 1M HCl. (83 18 65 61.8 vol.), Water 97 97.94 Input material (MR-3) purity (15.4 vol.) 98.6%

The compound PGT 230 may be obtained by de-protection of compound MR-3 using KOH. Briefly, 100 mg of compound MR-3 was dissolved in 6 ml of THF/methanol (1:1). The mixture was stirred for 15 min and then 6 ml of KOH 2M was added and the reaction was allowed to stir for 18 hours at room temperature. Organic solvent was evaporated completely and neutralized by HCl 1M. The precipitate was collected by vacuum filtration, washed with water several times, and dried overnight to give 83% of white powder of PGT 230 Dichloromethane/methanol (9:1) used as solvent for TLC. 1H NMR (CDCl3) δ (ppm): 7.85 (s, 2H, ArH), 7.16 (s, 2H, ArH), 4.6 (br, 1H), 3.56 (s, 2H, —CH₂—COO); 2.96 (s, 2H, —O—CH₂—C—CH).

Referring to the drawings, the embodiments of FIG. 2d-2f demonstrate chemical formulas of the tetrac derivatives of FIG. 2a-2c . However instead of the variable X comprising oxygen, the derivative compositions 215, 225 and 235 each comprise a sulfur substituted for variable X. Similar to the compositions 215, 225, 235 depicted in FIGS. 2d-2f , the derivatives 310, 320 and 330 describe another variation of the general formula 100. In the embodiments of FIG. 3a-3c , the thyrointegrin antagonist depicted substitutes R⁴ with a hydrogen, while R¹-R³ are substituted with iodine. Accordingly, because of the substitution of three iodine and a hydrogen, the thyroid antagonist shown in FIG. 3a-3c may be triiiodothyroacetic acid (triac) rather than tetrac. The compositions 310, 320 and 330 may summarily be identified as the derivatives monoamino-triac 310, diamino triac 320 and propargyl triac 330. In embodiments of the thyrointegrin antagonists, the derivatives of the thyroid antagonist use may not include an iodine, as opposed to the examples provided in FIGS. 2a-3c . The embodiments of FIG. 4a-4c demonstrate a thyrointegrin antagonist 410, 420, 430, wherein 10-R² are each substituted with a hydrogen and R³-R⁴ are each substituted with an isopropyl group.

Table 2 provided below describes a plurality of different substitutions that may be made into the variables of the general formula 100:

TABLE 2 Substitutions of the general formula for a thyrointegrin antagonists, wherein n₁ ≥ 0

Y X R¹ R² R³ R⁴ Amine, O or S H H H H diamine or propargyl Amine, O or S I H H H diamine or propargyl Amine, O or S H I H H diamine or propargyl Amine, O or S H H I H diamine or propargyl Amine, O or S H H H I diamine or propargyl Amine, O or S I I H H diamine or propargyl Amine, O or S I H I H diamine or propargyl Amine, O or S H H I I diamine or propargyl Amine, O or S I I I H diamine or propargyl Amine, O or S H I I I diamine or propargyl Amine, O or S I I I I diamine or propargyl Amine, O or S H H H H diamine or propargyl Amine, diamine or propargyl O or S

H H H Amine, diamine or propargyl O or S H

H H Amine, diamine or propargyl O or S H H

H Amine, diamine or propargyl O or S H H H

Amine, diamine or propargyl O or S

H H Amine, diamine or propargyl O or S

H

H Amine, diamine or propargyl O or S H H

Amine, diamine or propargyl O or S

H Amine, diamine or propargyl O or S H

Amine, diamine or propargyl O or S

Amine, diamine or propargyl O or S

H H H Amine, diamine or propargyl O or S H

H H Amine, diamine or propargyl O or S H H

H Amine, diamine or propargyl O or S H H H

Amine, diamine or propargyl O or S

H H Amine, diamine or propargyl O or S

H

H Amine, diamine or propargyl O or S H H

Amine, diamine or propargyl O or S

H Amine, diamine or propargyl O or S H

Amine, diamine or propargyl O or S

In some embodiments of the thyrointegrin antagonists of the current disclosure, the thyrointegrin antagonist of the general formula 100 may be conjugated, via the non-cleavable covalent bond of variable Y, to a non-biodegradable polymer (variable Z) as depicted by the general formula disclosed by embodiment 500 of FIG. 5. Suitable polymers that may be substituted for variable Z may include but are not limited to polyethylene glycol (PEG), α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, chitosan, alginic acid and hyaluronic acid, a combination of polymers thereof or any other non-cleavable polymer known or used by a person skilled in the art. The derivative 600 of the thyrointegrin antagonist depicts an example of a substitution of a PEG polymer for variable Z into the general embodiment of embodiment 500, wherein the PEG polymer has one or more repeating monomeric subunits as defined by the variable n₂. For instance, the variable n₂ may be any number of repeating monomer ≥1. The size of the PEG may vary depending on the number of repeating number of monomers in the PEG's chain. For example, in some embodiments, the size of the PEG may be 1,000-15,000 Daltons in some embodiments, whereas in alternative embodiments, the PEG may be 1000-4,000 Daltons or 4,000 to 6,000 Daltons or more.

In the exemplary embodiments of the current application, the thyroid hormone conjugated to the polymer may be tetrac, triac or a derivative thereof as shown in Table 1 above. FIG. 7a-7c depicts the chemical formulas of exemplary embodiments of tetrac conjugated via a non-cleavable covalent bond to the polymer PEG. For example, in FIG. 7a , the drawings depict a thyrointegrin antagonist 710 comprising a tetrac molecule covalently bound via a linker to a PEG polymer via a non-cleavable monoamine bond (N—C Bond). The resulting composition may be described as PEG-monoamino propyl tetrac (P-MAT). In the alternative embodiment 720 of FIG. 7b , the exemplary composition is a tetrac molecule bound via a linker to the PEG polymer via a non-cleavable diamine bond, resulting in a composition, which may be described as PEG-diamino propyl tetrac (P-DAT). In yet a third exemplary embodiment 730, the tetrac may be covalently bound to the PEG polymer via a non-cleavable triazole bond. The resulting composition 730 may be described as PEG-triazole tetrac (P-TAT).

FIG. 8 depicts a flow diagram 800 illustrating the one or more steps for conjugating PEG polymers to various active αvβ3 integrin thyroid antagonists via a non-cleavable linker bonded to PEG (1,000-15,000 Daltons), resulting in the formation of P-MAT, P-DAT and P-TAT. In the example methods provided, each composition of the present disclosure depicted using a Monomethoxy PEG as the polymer, a linker and multiple variations of the thyroid antagonist Tetrac, Triac and derivatives, provided during the conjugation steps such as DAT, MAT and TAT.

FIG. 8 depicts steps for creating P-MAT and P-DAT starting with a monomethoxy PEG (m-PEG-OH). Under step 801, the m-PEG-OH may be tosylated forming a mono-tosylated PEG 807 (m-PEG-OTS) and an m-PEG aldehyde 806. In step 802, the mono-tosylated PEG may be introduced to MAT 210 or a derivative thereof in step 802 to form P-MAT 710 through the click chemistry. Similarly, instead of introducing the mono-toslylated PEG 807 to an MAT 310, in step 803 the mono-tosylated PEG 807 may be introduced to a DAT 220 forming P-DAT 720 through the click chemistry as shown.

In order to form P-TAT from the starting monomethoxy-PEG, the mPEG-OH may via step 804 be converted into m-PEG-azide by tosylating the m-PEG-OH to mono-tosylated PEG 807 and converting the mon-tosylated PEG 807 into m-PEG-azide 808 by combining the mono-tosylated PEG 807 with NaN₃. The m-PEG-azide 808 may in step 805 combine with a propargyl tetrac 230, creating a triazole bond resulting in P-TAT 730.

It should be noted that for each of the examples provided in the drawings and as described throughout this application, were prepared using commercially available chemicals that have been used without further purification. All solvents were dried and anhydrous solvents were obtained using activated molecular sieves (0.3 or 0.4 nm depending on the type of solvent). All reactions (if not specifically containing water as reactant, solvent or co-solvent) are performed under Ar or N₂ atmosphere, in oven-dried glassware. All new compounds gave satisfactory 1H NMR and mass spectrometry results. Melting points were determined on an Electro thermal MEL-TEMP® melting point apparatus and then on a Thomas HOOVER Uni-mel capillary melting point apparatus. Infrared spectra recorded on a Thermo Electron Nicolet Avatar 330 FT-IR apparatus. UV spectra obtained from a SHIMADZU UV-1650PC UV-vis spectrophotometer. The solution-state NMR experiments were all performed a Bruker Advance II 800 MHz spectrometer equipped with a cryogenically cooled probe (TCI) with z-axis gradients (Bruker BioSpin, Billerica, Mass.) at the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute (RPI, Troy, N.Y.). All tubes used were 5 mm outside diameter. NMR data were referenced to chloroform (CDCl3; 7.27 ppm 1H, 77.20 ppm 13C) or DMSO-d6 (δ=2.50 ppm, 38.92 ppm 13C) as internal reference. Chemical shifts δ are given in ppm; multiplicities are indicated as s (singlet), d (doublet), t (triplet), q (quartet), m (multiplet) and br (broad); coupling constants, J, are reported in Hz. Thin layer chromatography was performed on silica gel plates with fluorescent indicator. Visualization was accomplished by UV light (254 and/or 365 nm) and/or by staining in ceric ammonium molybdate or sulfuric acid solution. Flash column chromatography performed following the procedure indicated in J. Org. Chem. 43, 14, 1978, 2923-2925, with 230-400 mesh silica gel. High-resolution Mass Spectral analysis performed on either an Applied Biosystems API4000 LC/MS/MS or Applied Biosystems QSTAR XL mass spectrometers.

In some embodiments, the polymer-conjugated thyrointegrin antagonists described throughout this disclosure may be bi-functional or tetra-functional compositions. The term “bi-functional” may refer to a polymer conjugated thyroid antagonist having a two thyroid antagonists or derivatives thereof conjugated via a non-cleavable covalent bond to the same polymer (Z) of the general formula 500. One of a bifunctional composition can be seen in FIG. 9, wherein the thyrointegrin antagonist 900 comprises a PEG polymer conjugated on two sides of the embodiment 900 via a carbon atom linker and a non-cleavable bond represented by variable Y to a thyroid hormone antagonist. FIG. 10a-10c provides examples of one or more specific substitutions of the variables depicted in the embodiments 900 of FIG. 9.

For instance, in FIG. 10a , the PEG polymer having one or more repeating subunits denoted by variable n₂, may be conjugated using two different amino bonds and a carbon linker attaching to a thyroid hormone antagonist comprising tetrac or a tetrac derivative. As shown in FIG. 10a , the thyrointegin receptor antagonist may comprise two MAT molecules, wherein each MAT molecule may be conjugated to the outermost PEG molecule of the PEG polymer via the non-cleavable amino linkage. The composition 1010 may therefore be referred to as polyethylene glycol-bi-monoamine propyl tetrac (P-bi-MAT) 1010.

Similar to the composition 1010 of FIG. 10a , the composition of FIG. 10b may replacement each of the MAT's in the bifunctional P-bi-MAT with a non-cleavable diamino bond forming the conjugation forming the linkage between the PEG polymer and the thyroid hormone antagonist. Accordingly, the composition 1020 comprising diamino bonds may be summarily described as polyethylene glycol-bi-diamino propyl tetrac (P-bi-DAT) 1020. In one or more alternative embodiments, instead of using a MAT 210 or a DAT 220, the thyrointegrin antagonist being conjugated via the non-cleavable bond the PEG polymer may be a plurality of PGT 230 molecules. As shown in FIG. 7c , the PGT molecule and derivatives thereof may form a non-cleavable triazole bond between the polymer (PEG) and PGT, resulting in the formation of a P-TAT 730. Similar to the P-bi-MAT 1010 and P-bi-DAT 1020, P-TAT may form the bifunctional variation thereof shown in FIG. 10c comprising a triazole bond conjugating each thyroid hormone antagonist or derivative thereof to the PEG polymer. The bi-functional molecule may be referred to as polyethylene glycol-bi-triazole-tetrac (P-bi-TAT).

FIG. 11 describes one or methods for synthesizing the bi-functional thyrointegrin antagonists P-bi-MAT 1010, P-bi-DAT and P-bi-TAT using a PEG (depicted as OH-PEG-OH in embodiment 1100. In the first step of method 1100, the PEG may in step 1101 be tosylated to form bi-tosylated PEG. In one example described below, steps for toslylating the PEG may be performed as described in the following example:

HO-PEG-OH (1.5 g, 0.25 mmol, eq=1) dissolved in 50 ml DCM and stirred in for 15 minutes. 4-toluenesulfonyl chloride (0.38 g, 2.02 mmol, eq=8) and 1 ml TEA was added to mixture. Reaction stirred in room temperature for overnight. Reaction diluted in DCM and washed by HCl 1N, (2×), brine 1×. Mixture concentered and DCM removed completely and result re-crystallized by ethyl acetate overnight. White powder collected after filtration and residue 1.4 g obtained.

The second step of the method 1100 may vary depending on the desired final product looking to be achieved. If the desired final thyrointegrin antagonist is P-bi-MAT 1010, the bi-tosylated PEG may be introduced via step 1102 to the presence of MAT 210 resulting in the replacement of the tosyl groups in the bi-tosylated PEG with a MAT 210 covalently bound via amino bonds to each side of the PEG polymer creating P-bi-MAT. Similarly, the tosyl groups of the bi-tosyl-PEG may be replaced with DAT 220 groups in step 1103. As the bi-tosyl PEG is introduced in the presence of the DAT, the DAT may bind to the PEG via one or more covalent diamino bonds resulting in the formation of P-bi-DAT 1020.

If, however, the desired goal is to obtain a P-bi-TAT 1030, one or more additional steps may be performed. Firstly, in step 1104, a bi-Azido-PEG may be formed from the bi-tosylated-PEG of step 1101. One example of an embodiment of the steps for synthesizing bi-Azido-PEG may be described as follows:

Synthesis of bi-Azido-PEG (MW=4000)

sTO-PEG-OTs (2500 mg, ˜0.5 mmol, eq.=1) dissolved in 20 ml DMF and then 3000 mg NaN₃ is added to solution and the reaction is set to 80° C. for overnight. 200 ml water is added to the solution and extracted by DCM three times. The organic phases combined and washed by brine and dried over MgSO₄. The solvent is removed and recrystallized by ethyl acetate at −20 C and filtered, producing 1750 mg of bi-azido modified PEG obtained.

Once the bi-Azido modified PEG is obtained in step 1104, the bi-Azido-PEG may be reacted in step 1105 the presence TAT 730 in order to form P-bi-TAT 1030 as shown in FIG. 11. The following example demonstrates in further detail the synthesis of the reaction from bi-Azido-PEG to P-bi-TAT 1030;

Synthesis of P-bi-TAT (MW=4000)

Bi-Azido-PEG (N3-PEG-N3) (2000 mg, 0.5 mmol, eq=1) dissolved in 8 ml DMF and then 1570 mg of TAT (2 mmol, eq=4) added to reaction. 286 mg CuBr (2 mmol, eq=4), and 814 μl of N,N,N′,N″,N″-Pentamethyldiethylenetriamine (PMDETA) (4 mmol, eq=8) dissolved in 2 ml DMF and added to solution and set the reaction in 60-65 C for overnight. Reaction cooled down to room temperature and diluted the reaction in 100 ml DCM. Cooper removed by passing through aluminum oxide column which negatively activated by carboxylic acid and wash several times by DCM and then concentrated mixture to 100 ml. Washed the mixture by 200 ml water (3×) and brine (2×). 5) The organic phase dried over MgSO₄, removed the DCM and finally re-crystallized the final product by adding 200 ml of ethyl acetate. Repeated the recrystallization two more times and yellowish powder obtained by filtration.

The phenolic hydroxyl group (—OH) of the thyroid analogs is an important site for their modification and as a target site for converting tetrac to an integrin antagonist without any changes to the carboxylic acid moiety of tetrac. The molecular structure tetraiodothyroacetic acid (tetrac) is synthetically modified with propargyl bromide to prepare an alkyne modified tetrac, Propargyl Tetrac (PGT), {4-[3, 5-diiodo-4-(prop-2-yn-1-yloxy) phenoxy]-3, 5-diiodophenyl} acetic acid; molecular weight, 785 Daltons). PGT conjugated to O, O′-Bis (azide) polyethylene glycol (molecular weight, 4,050 Daltons) via click chemistry to yield p-bi-TAT with a molecular weight of 5,620 Daltons, as shown in FIG. 11 and in the scheme for P-bi-TAT synthesis demonstrated below:

P-bi-TAT Synthesis:

Chemical Name: O,O′-Bis({4-[3,5-diiodo-4-(1-methylen-1,2,3-triazol-4-ylmethoxy)phenoxy]-3,5-diiodophenyl}acetic acid) polyethylene glycol. Physical Appearance: Yellowish brown powder Solubility: Soluble in water at 50 mg/ml; in Phosphate buffer, pH 8.0 at 100 mg/ml; in 10% Ethanol at 150 mg/ml, and in 50% propylene glycol at 200-300 mg/ml.

In some embodiments of the polymer conjugated thyrointegrin antagonists, the compositions may not only be mono-functional as shown by the general formula 600 or bi-functional as shown by the composition having the general formula 900, but may further be tetra-functional as demonstrated by the examples of FIG. 12. For example, similar to the methods for preparing P-bi-MAT 1010, P-bi-DAT 1020 and P-bi-TAT as shown in FIG. 11 and described above, tetra functional derivatives of P-tetra-MAT 1210, P-tetra-DAT and P-tetra-TAT may be synthesized. The synthetization steps for preparing the tetra functional thyrointegrin antagonists shown in FIG. 12 may be analogous to the steps for preparing mono-conjugated and bi-conjugated derivatives shown in the example methods of FIGS. 8 and 11.

For example, instead of using m-PEG or PEG as the starting material, a tetra-PEG may be used. In step 1201, the tetra-PEG may be tosylated into P-tetra-OTS and subsequently reacted in the presence of P-MAT 710 or P-DAT 720 to form P-tetra-MAT 1210 and P-tetra-DAT 1220 respectively. Likewise, similar to synthesis of P-TAT 730 and p-bi-TAT 1030, p-tetra-TAT 1230 may be synthesized by first converting toslylated P-tetra-OTS into P-tetra-azido as shown in step 1204. Subsequently, in step 1205, the p-tetra-azido composition may be reacted in the presence of p-TAT 730 to create the p-tetra-TAT 1230.

In alternative embodiments of the thyrointegrin antagonists, the polymer, Z of the general formula 500, may be substituted for an α, β, or γcyclodextrin, as shown by the general formula 1300 of FIG. 13a . In the formula 1300, the variable n₃=1, 2 or 3 repeated monomeric subunits of the cyclodextrin, wherein the number of repeated subunits may identify the cyclodextrin used as the polymer in the conjugated thyrointegrin antagonist. For example, when n₃=1, the cyclodextrin is α-cyclodextrin, n₃=2 the cyclodextrin is β-cyclodextrin and when or n₃=3, the cyclodextrin may be γ-cyclodextrin. Similar to the other thyrointegrin antagonist derivatives described by the general formula 100 and 500 above, the substitutions for R¹, R², R³, R⁴, X, Y and n₁ may occur in a similar manner in formula 1300. FIGS. 13b-13d provide examples of cyclodextrin conjugated thyrointegrin antagonists. Specifically, in FIG. 13b , a cyclodextrin-monoamino-propyl tetrac (C-MAT) 1310 is provided, whereas in FIG. 13c a cyclodextrin-diamino-propyl tetrac (C-DAT) 1320 is exemplified. Moreover, FIG. 13d depicts an example of the chemical structure of cyclodextrin-triazole tetrac (C-TAT) 1330.

The methods of synthesizing the C-MAT 1310, C-DAT 1320 and C-TAT 1330 follow similar synthetization steps as alternatively conjugated variations of the P-MAT 710, P-DAT 720 and P-TAT 730 described previously. As shown in FIG. 14a and FIG. 14b , synthesizing may begin at step 1401 by tosylating the cyclodextrin polymer to a tosylated-cyclodextrin. In order to create C-MAT 1310 or C-DAT 1320, the MAT 210 or DAT 220 may be reacted in the presence of the tosylated-cyclodextrin in steps 1402 or 1403 respectively. In order to synthesize C-TAT 1330, the tosylated-cyclodextrin resulting from step 1401 may be further reacted in step 1404 to create cyclodextrin-azido composition, which may be further reacted in the presence of PGT 230 in step 1405, resulting in the synthetization of C-TAT 1330.

The following examples describe the synthetization of cyclodextrin conjugated thyrointegrin antagonists in more detail with reference to the method of synthesizing depicted in FIG. 45:

Synthesis of C-TAT—Synopsis on the Synthesis:

The phenolic hydroxyl group (—OH) of thyroid analogs is an important site for their modification and as a target site for converting tetrac to an integrin antagonist without any changes to the carboxylic acid moiety of tetrac. The molecular structure tetraiodothyroacetic acid (tetrac) is synthetically modified with propargyl bromide to prepare an alkyne modified tetrac, Propargyl Tetrac (PGT), {4-[3, 5-diiodo-4-(prop-2-yn-1-yloxy) phenoxy]-3, 5-diiodophenyl}acetic acid; molecular weight, 785 Daltons). PGT conjugated to mono-6-azide-deoxy-6-β-cyclodextrin via click chemistry to yield β-C-TAT.

Beta C-TAT: Mol. Wt.: 1,944.89 Daltons Chemical Name: 6-({4-[3,5-diiodo-4-(1-methylen-1,2,3-triazol-4-ylmethoxy)phenoxy]-3,5-diiodophenyl}acetic acid)-6-deoxy-β-cyclodextrin

Synthesis of γ-C-TAT—Synopsis on the Synthesis:

The phenolic hydroxyl group (—OH) of thyroid analogs is an important site for their modification and as a target site for converting tetrac to an integrin antagonist without any changes to the carboxylic acid moiety of tetrac. The molecular structure tetraiodothyroacetic acid (tetrac) is synthetically modified with propargyl bromide to prepare an alkyne modified tetrac, Propargyl Tetrac (PGT), {4-[3, 5-diiodo-4-(prop-2-yn-1-yloxy) phenoxy]-3, 5-diiodophenyl}acetic acid; molecular weight, 785 Daltons). PGT conjugated to mono-6-azide-deoxy-6-γ-cyclodextrin via click chemistry to yield γ-C-TAT with a molecular weight of 2,108 Daltons. Detailed Schematic for the synthesis of C-TAT is as shown below.

Structure of C-TAT Chemical Name: 6-({4-[3,5-diiodo-4-(1-methylen-1,2,3-triazol-4-ylmethoxy)phenoxy]-3,5-diiodophenyl}acetic acid)-6-deoxy-γ-cyclodextrin. Mol. Wt.: 2,108 Daltons

In some alternative embodiments of the polymer conjugated thyrointegrin antagonists having the general formula 500, the polymer described by the variable Z may be substituted with an alginic acid polymer as shown by the examples depicted in FIG. 15a-15c . For instance, in FIG. 15a , alginic acid polymer may be conjugated to a P-MAT 710 resulting in the formation of alginic acid-monoamino-propyl tetrac (A-MAT) 1510 or a derivative thereof, wherein the variable n₄ defines a number of repeating monomer subunits of the alginic acid. The variable n₄ may be any number of repeating subunits ≥1. In FIG. 15b , an alternative conjugation using a DAT 720 to the alginic acid polymer may be used or a derivative thereof. The resulting conjugation of the alginic acid polymer with a DAT 720 may be referred to as Alginic acid-diamino-propyl tetrac (A-DAT) 1520, whereas the conjugation between TAT 730 and alginic acid results in the formations of alginic acid-triazole tetrac (A-TAT) 1530 or a derivative thereof.

The synthetization of A-MAT 1510, A-DAT 1520 and A-TAT 1530 follows a slightly altered set of steps compared with the synthetization of the previous polymer conjugations of PEG and cyclodextrin above. As shown in FIG. 16a , synthesizing method starts with the alginic acid polymer. Instead of tosylating the polymer, step 1601 reacts the alginic acid with N-hydroxy-succinimide, attaching the N-hydroxy-succinimide (NHS) to the carboxyl group of the alginic acid. In steps 1602 and 1603, the NHS may be removed in a substitution reaction by introducing MAT 210 (step 1602) or DAT 220 (step 1603) to replace the NHS of the alginic acid with either MAT 210, forming A-MAT 1510 or DAT 220 forming A-DAT 1520.

FIG. 16b depicts the method steps for preparing A-TAT 1530 from an alginic acid starting material. The alginic acid is reacted with the NHS to form NHS-alginic acid in step 1601. In step 1604, the NHS-alginic acid undergoes a reaction with an azido compound, replacing the NHS attached to the carboxyl group of the alginic acid with the azido compound resulting in a alginic acid-azido compound as shown in FIG. 16b . Lastly, the alginic acid-azido compound formed because of step 1604 may be further reacted in step 1605 in the presence of PGT 230 to form a triazole bond with the N3 of the azido group, generating A-TAT 1530.

In some alternative embodiments of the polymer conjugated thyrointegrin antagonists having the general formula 500, the polymer described by the variable Z may be substituted with a hyaluronic acid polymer as shown by the examples depicted in FIG. 17a-17c . For instance, in FIG. 17a , the hyaluronic acid polymer may be conjugated to a P-MAT 710 resulting in the formation of hyaluronic acid-monoamino-propyl tetrac (H-MAT) 1710 or a derivative thereof, wherein the variable n₄ defines a number of repeating monomer subunits of the hyaluronic acid. The variable n₄ may be any number of repeating subunits ≥1. In FIG. 17b , an alternative conjugation using a DAT 720 and the hyaluronic acid polymer may be used or a derivative thereof. The resulting conjugation of the hyaluronic acid polymer with a DAT 720 may be referred to as hyaluronic acid-diamino-propyl tetrac (H-DAT) 1720, whereas the conjugation between TAT 730 and hyaluronic acid results in the formations of hyaluronic acid-triazole tetrac (H-TAT) 1730 or a derivative thereof.

The synthetization of H-MAT 1710, H-DAT 1720 and H-TAT 1730 follows a similar set of synthetization steps to the polymer conjugated alginic acid methodology of FIG. 16a-16b previously described above. As shown in FIG. 18a , synthesizing method starts with the hyaluronic acid polymer. Instead of tosylating the polymer, step 1801 reacts the hyaluronic acid with NHS to the carboxyl group of the hyaluronic acid polymer. In step 1802 and 1803, the NHS may be removed in a substitution reaction by introducing MAT 210 (step 1802) or DAT 220 (step 1803) to replace the NHS of the hyaluronic acid with either MAT 210, forming H-MAT 1710 or DAT 220 forming H-DAT 1720.

FIG. 18b depicts the method steps for preparing H-TAT 1730 from a hyaluronic acid starting material. The hyaluronic acid is reacted with the NHS to form NHS-hyaluronic acid in step 1801. In step 1804, the NHS-hyaluronic acid undergoes a reaction with an azido compound, replacing the NHS attached to the carboxyl group of the hyaluronic acid with the azido compound resulting in a hyaluronic acid-azido compound as shown in FIG. 18b . Lastly, the hyaluronic acid-azido compound formed because of step 1804 may be further reacted in step 1805 in the presence of PGT 230 to form a triazole bond with the N3 of the azido group, generating H-TAT 1730.

Polymer-Conjugated Thyrintegrin Antagonist Methods of Use

Example 1 Anti-Angiogenesis Efficacy

Mouse Matrigel-Growth Factors Implant Angiogenesis Model:

The mouse Matrigel model was performed in accordance with institutional guidelines for animal safety and welfare. Female mice C56/BL aged 5-6 weeks and body weights of 20 g were purchased from Taconic Farms (Hudson, N.Y., USA). The animals were maintained under specific pathogen-free conditions and housed 4 animals per cage, under controlled conditions of temperature (20-24° C.) and humidity (60-70%) and a 12 h light/dark cycle. The in vivo study carried out in the animal facility of the Veterans Affairs (VA) Medical Center, Albany, N.Y., and the experimental protocol approved by the VAIACUC. Mice were acclimated for 5 d prior to the start of experiments. Matrigel Matrix High Concentration with growth factors to promote the angiogenesis and the mix was injected four times subcutaneously at 100 μl/animal. Animals in the control group injected just with Matrigel in 100-μl volume.

Polymer Conjugated DAT, TAT or MAT derivatives were tested at three different doses (10, 30, 100 μg/10 μl). All groups have three mice per group, with 12 Matrigel subcutaneous injections per group. At day 14-post plug implant, all animals were sacrificed and hemoglobin contents were quantitated using spectrophotometry. FIG. 21 depicts representative data for P-bi-TAT and its effective anti-angiogenesis efficacy against growth factors. As it can be seen in FIG. 21, the anti-angiogenic effects of P-bi-TAT and the other thyrointegrin antagonists measured during this study demonstrated a dose dependent response on angiogenesis, as evident by the measured hemoglobin levels.

Example 2: Determination of Hemoglobin (Hb) Levels (Measure of Angiogenesis Index)

Matrigel plug hemoglobin (Hb) content was indexed as a measure of new vascularity formation. Briefly, Matrigel plugs placed into a 0.5 ml tube containing double distilled water and then homogenized for 5-10 min. The samples were subjected to centrifugation at 4,000 rpm for 10 min and then the supernatants were collected. A volume of 50 μl of supernatant were mixed with 50 μl of Drabkin's reagent and allowed to sit at room temperature for 15-30 min, after which 100 μl was placed in a 96-well plate and absorbance was measured at 540 nm with a Microplate Manager ELISA reader. The Hb concentration was expressed as mg/ml based on comparison with a standard curve.

Example 3: Mousa Subcutaneous Cancer Cell Implant

The anti-angiogenesis Efficacy against tumor-angiogenesis was tested using ovarian cancer cell line (OVCAR3) implanted into Matrigel nude female mice. After 14 days of daily treatment (1 mg/kg, SC, QD) with polymer conjugated DAT, MAT and TAT, Matrigel tumor implant removed and analyzed for Hemoglobin. The representative data of the anti-angiogenesis effects against tumor-mediated angiogenesis is depicted as a function the hemoglobin measurement shown by the data of FIG. 22.

Example 4: Expression of αvβ3 in Different Cancer Cell Lines (Flow Cytometry Analysis)/Confocal Imaging

Cells were cultured overnight and cells were collected after a trypsin treatment. Then cells were incubated with FITC conjugated anti αvβ3 for 30 minutes, washed with PBS and the αvβ3 expression studied using flow cytometry as shown in FIG. 23 and Table 3 below. Additionally, the αvβ3 expression levels were observed under a confocal microscope as shown in FIG. 24.

TABLE 3 Expression of αvβ3 for Various Cancer Cells (Flow Cytometry) Expression of Cancer Cells Cell Lines αvβ3 (%) Glioblastoma cell line U87 97 Primary human GBM 021913 GBM 90 Primary human GBM 052814 GBM 95 Primary human GBM 101813 GBM 85 Bladder CANCER 253JBV 91 Lung carcinoma H1299 31 Pancreatic cancer SUIT2 32 Pancreatic cancer MPANC 96 22 Breast cancer MDA MB 21

Example 5: Acute Myeloid Leukemia Model: Transgenic Mice (NOD.Cg-Prkdcscid) Male

THP-1-luc cells were injected intraperitoneally (5×10⁶ cells in 0.1 ml) into a Control (vehicle) arm and in polymer conjugated diaminotetrac (P-DAT 720) or polymer conjugated triazole tetrac (P-TAT 730) at 3 mg/kg, subcutaneously once a day for 3 weeks. Blood samples were collected before injecting cells, before treatment, and once a week after treatment. Animals terminated after three weeks, carried out via IVIS images of limbs, liver spleen and heart & lungs for luminescent signal intensity of the TPH-1 cells. Additionally, bone marrow smears prepared and Leishman stain was carried out. FIG. 25 describes the representative data of the leukemia model wherein a greater number of blast cells in the control were observed in comparison with the polymer conjugated P-DAT 720 and P-TAT 730.

Example 6: Anti-Cancer Efficacy: Effect of Polymer-Conjugated DAT and DAT on U87MG Xenografts in the Nude Mouse

The xenograft model of glioblastoma is a standard model for study of GBM. In the current studies, athymic, immunodeficient NCr nude mice aged 5-6 weeks and weighing 18-20 g were used. Animals were provided with ad libitum access to water and food. Animals allowed to acclimatize to the facility for 5 days prior to study. Cultured U87MG-luc cells were harvested and implanted subcutaneously (s.c.) in each flank (5×10⁶ cells in 100 uL volumes containing 50% Matrigel) Tumors were grown for 2 days (to an initial volume of 150-250 mm³) before administration of the control, C-DAT 1320, C-TAT 1330, P-TAT 730, P-bi-DAT 1020, P-bi-TAT 1030. Immediately before initiation of treatment at 2 days after implantation, animals were divided into control and treatment groups containing similar distributions of tumor volumes (calipers measurement). Polymer conjugated P-DAT 720 and P-TAT 730 (3 mg or 10 mg/kg body weight) was administered daily s.c. to two groups of animals×21 days, and vehicle (PBS, pH 8.0/0.5% ethanol) was administered daily s.c. to one group of animals as control×21 days. There were 4 animals and 8 grafts/treatment group. The control group and one group of drug-treated animals humanely sacrificed at 21 days; the second group of drug-treated mice observed off therapy for an additional 22 days to detect any tumor re-growth. The second drug-treated group thus observed for a total of 43 days. Tumors harvested and weighed, then fixed, sliced and subjected to hematoxylin and eosin (H&E) staining. Microscopic slides accommodated the full diameter of the control tumors. See representative FIGS. 25-26 for IVIS imagining of GBM tumors treated with the various polymer-conjugated thyrointegrin antagonists.

Data presented demonstrate that polymer conjugated P-DAT 720 and P-TAT 730 are effective in subcutaneous U87MG glioblastoma xenografts. Administered systemically for 21 days, the drug reduced tumor volumes by fully suppressing angiogenesis, inducing extensive necrosis, and causing apoptosis. While polymer conjugated P-DAT 720 and P-TAT 730 have a single molecular target on αvβ3, the target differentially regulates a network of intracellular signaling pathways and plasma membrane functions that control specific gene transcription and cell surface vascular growth factor receptor functions that are highly relevant to cancer and cancer-relevant angiogenesis. Little αvβ3 is expressed by or activated in non-dividing, non-malignant cells, thus restricting actions of polymer conjugated P-DAT 720 and P-TAT 730 to tumor cells and tumor-associated blood vessel cells. Data in FIGS. 28-30 describe the effects of these various polymer conjugated P-DAT 720 and P-TAT 730 on tumor progression and regression.

The data presented in FIG. 28-30 describes the polymer conjugated thyrointegrin antagonists at both 3 and 10 mg/kg dosages dramatically reduced tumor weight. Xenografts in the second group of treated mice, observed for an additional 22 days with no further drug exposure (OFF treatment group), continued to decrease in size, achieving >95% decrease in tumor weight (**p<0.01) over the study duration of 43 days at both the 3 and 10 mg/kg doses. The observations presented in FIGS. 28-30 are further supported by histologic assessment of cell viability in xenografts harvested at day 21 (FIG. 31) with P-bi-TAT 1030 as a representative polymer conjugated P-TAT 730.

Histologic evaluation of paraffin-embedded tissue sections were stained (hematoxylin and eosin), and each section was coded. The area of the section measured with a stage micrometer, and the percentage of viable vs. necrotic tumor, manifested by loss of cell density, dissolution of the plasma membrane and loss of nuclear structure estimated visually. The number of mitoses and apoptotic cells per high power field was counted for 5 fields of viable tumor areas and averaged per tissue section. The degree of vascularization varied in the viable areas and this was graded from 1-4. Reductions in cell viability achieved by day 21 were 60-70% in the xenografts exposed to 3 mg/kg and 10 mg/kg dosages of P-bi-TAT 1030 (**p<0.001). These findings are consistent with the systematic de-vascularization of tumors leading to necrosis and the multiple pro-apoptotic mechanisms that polymeric P-DAT 720 or P-TAT 730 induce. IVIS Imaging for viable cells (FIG. 32) and histological data (FIG. 31) confirm the effect of P-bi-TAT 1030 as a representative polymer conjugated P-DAT 720 or P-TAT 730 in affecting cancer cell survival.

Example 7: Kinetics of Cy5 Labeled P-Bi-TAT and Other Polymer Conjugated Thyrointegrin Antagonist Derivatives

Each group of animals was provided with orthotropic implants (GBM) and after tumor growth in the brain and subcutaneously implanted GBM Xenografts. Polymer conjugated MAT 210, TAT 230 or DAT 220 derivatives were injected subcutaneously with P-bi-TAT-Cy5 and other polymer conjugated TAT 230 or DAT 220 derivative-Cy5. IVIS imaging was performed immediately after injection and at 30 min, 1 h, 2 h, 3 h, 4 h to detect the fluorescence intensity at the orthotropic brain xenograft tumor site (brain) and subcutaneous xenografts tumors. FIG. 33 is provided as a representative IVIS imaging illustrating optimal and comparable delivery to GBM in the brain or subcutaneously implanted tumors. The graphs depicted in FIGS. 34 and 35 describe the kinetics of the thyrointegrin antagonist derivatives' uptake into GBM tumors in the brain or subcutaneously implanted tumors. FIGS. 34-35 describe the effects of the polymer conjugated thyrointegrin antagonist derivatives containing MAT 210, DAT 220 and TAT 230 over time including bifunctional embodiments thereof.

Cy5 signals of P-bi-TAT 1030 and polymer conjugated P-TAT 730 derivative-Cy5 was seen in the brain at 30 minutes and sustained for the 4 hours of monitoring with IVIS. Animal terminated after 4 hours and Cy5 signals detected in the brain GBM tumor and subcutaneous GBM tumor xenografts. Cy5 signal was comparable in the brain GBM tumor and the subcutaneous GBM tumor xenografts. FIG. 36 illustrate the comparable uptake into GBM in the brain and subcutaneously implanted tumor xenografts.

Example 8: Effect of P-Bi-TAT on GBM (U87-Luc) Xenografts (Orthotropic and Subcutaneous)

Glioblastoma cells: U87-luc cells implanted orthotopically at 0.2×10⁶ cell in 20 ul, in Matrigel and subcutaneously xenografted at 2×10⁶ cells/implant with Matrigel in athymic female mice. Animals treated with polymers conjugated thyrointegrin antagonists, including derivatives of P-DAT 720, P-TAT 730 and bifunctional derivatives thereof for 7 days after 1 day post-implant and IVIS imaging of the brain tumor and subcutaneous tumor xenograft. FIG. 37 describe the dose dependent suppression of the tumor using P-bi-TAT 1030, including the suppression of cell viability in brain GBM tumor and subcutaneous GBM tumor. FIGS. 38-40 depict the measurable dose-dependent effects of p-bi-TAT 1030 on brain GBM tumor and subcutaneous GBM tumor including the effect on luminescent signals of GBM in the brain, average tumor weight and bioluminescent intensity.

Example 9: Effect of P-Bi-TAT on Pancreatic Cancer SUIT 2 Xenografts

Female NCr mice (Taconic Farms, Hudson, N.Y.) for in vivo studies obtained at 5-6 weeks of age (20 gm body weight) and maintained under specific pathogen-free conditions, and food and water provided ad libitum. The animals allowed to acclimate for 5 days. Cultured human SUIT 2 cells were harvested and implanted subcutaneously (s.c.) in each flank of the mice. Inocula comprising 100 μL, 50% Matrigel °, and containing 2×10⁶ tumor cells was prepared. Tumors were grown for 7 days, at which time the animals were randomized into control and P-bi-TAT groups (6 animals/group, 12-carcinoma grafts/group). Starting on day 0, drug was administered at 3 or 10 mg of P-bi-TAT/kg body weight, daily for 20 days (to experimental day 19). Control animals received vehicle (PBS) daily. Animals were sacrificed on experimental day 20. Tumors were harvested and the weight of the tumors were measured. Tumors were formalin-fixed, imbedded in paraffin and sliced.

Effectiveness of radiation therapy, alone and in conjunction with P-bi-TAT was also assessed. The Radiation treatment was one Gy administered to right flank xenografts on days 10 and 17. Geometry of flank exposure excluded radiation exposure to the left flank of study animals, so that the left flank served as a control in the radiation studies.

The effects of a representative polymer-conjugated thyrointegrin antagonist (P-bi-TAT 1030) on tumor weight, cell viability and cell necrosis was studied. Anticancer efficacy of P-bi-TAT on pancreatic cancer SUIT 2 xenograft weight, cell viability and cell necrosis shown in FIG. 41a-41c . The Tumor weight reduction after 20 days was 55% with the administration of P-bi-TAT at 3 mg/kg and 65% at 10 mg/kg (each ***P<0.001 vs. control) (FIG. 41a ). Percent reduction in tumor cell viability was insignificant at a drug concentration of 3 mg/kg and was 43% at 10 mg/kg (***P<0.001 vs. control) as shown in FIG. 41b . The increase in % cell necrosis in tissue sections was not significant at 3 mg/kg of P-bi-TAT, but there was more than a doubling of necrosis at a dose 10 mg/kg (***P<0.001 vs. control) as shown by the data in FIG. 41C. Thus, in these short-term studies with P-bi-TAT, there were desirable alterations in tumor size and in histologically estimated cancer cell viability and necrosis.

Interactions of Radiation Exposure and P-Bi-TAT Administration:

The effects of radiation exposure, alone, and radiation in conjunction with P-bi-TAT on pancreatic cancer SUIT 2 xenograft weight, cell viability and cell necrosis is depicted in FIG. 42 a-42 c. Radiation treatment, alone, at one Gy to the right flank xenografts caused a decrease in tumor weight of these xenografts of 38% vs. left flank xenografts, which were unexposed to radiation (FIG. 42a ). The combination of radiation and the exemplary embodiment the polymer conjugated thyrointegrin antagonist tested P-bi-TAT 1030 resulted in further decreases in tumor size of 71% (3 mg P-bi-TAT/kg) and 77% (10 mg P-bi-TAT/kg) (each ***P<0.001 vs. non-irradiated control). There was no P-bi-TAT dose effect on tumor weight when drug and radiation combined.

As shown in FIG. 42b , a decrease in % cell viability was shown at 1 Gy without P-bi-TAT was without statistical significance, but the combination of radiation and drug at 3 mg/kg resulted in a 54% decrease in viability and a 68% decrease was observed at 10 mg/kg (each **P<0.05 vs. non-irradiated control xenografts). Moreover, an upward trend in necrosis with radiation, alone, was not statistically significant as shown by the graphical data presented in FIG. 42c , however, the combination of radiation and P-bi-TAT at 3 mg/kg resulted in an increase of necrosis of 65% and 70% at 10 mg/kg of (each **P<0.05 vs. non-irradiated control). Moreover, FIG. 43 further demonstrates data showing the interactions between P-bi-TAT (3 and 10 mg/Kg, SC QD) and irradiation of pancreatic tumors at 1 and 5 Gy in comparison to controls.

Thus, based on the data provided in FIG. 42a-42c , it can be concluded that there is an unexpected combination therapy producing important additive effects on tumor weight reduction and on cell necrosis and viability. The anti-tumor effectiveness of the thyrointegrin antagonists, polymer conjugated thyrointegrin antagonists and bifunctional embodiments thereof, including the exemplary composition of P-bi-TAT on tumor mass at 3 mg/kg body weight is near maximal for the agent, i.e., results with dosages of 3 mg/kg and 10 mg/kg are comparable. The survey of histological changes obtained with and without radiation, however, suggests that 10 mg P-bi-TAT/kg was more effective than 3 mg/kg. The foregoing set of xenograft observations establish that the polymer conjugated thyrointegrin antagonists, such as P-bi-TAT are a highly effective therapeutic intervention in pancreatic carcinoma xenografts in the standard experimental context.

Example 10: Safety Studies, C57BL6 Mice

Preclinical toxicology of a representative of the polymer conjugated thyrointegrin antagonist antiangiogenic agent of P-bi-TAT was pursued in 5-to-6 week-old C57BL6 mice, treated for 14 days with varying doses of P-bi-TAT. The treatment groups were control (vehicle), 1 mg/kg, 3 mg/kg, 10 mg/kg, 30 mg/kg, 100 mg/kg and 330 mg/kg P-bi-TAT, administered daily s.c. for 14 days. Each treatment group consisted of 5 male and 5 female animals, and animal weights were measured twice weekly. Mice terminated after 14 days and blood samples collected from the retro-orbital venous plexus. Blood samples centrifuged, and harvested plasma was stored at −80° C. until subjected to analyses described below.

Liver function was estimated by measurement in stored plasma of alanine transaminase (ALT) and aspartate transaminase (AST) activities (Colorimetric kit, Biovision, Inc., Milpitas, Calif.) the data for which is shown in FIG. 44. Cardiac troponin I (cTnI) levels in plasma were measured by an ELISA method (Life Diagnostics, West Chester, Pa.) as an index of myocardial damage (FIG. 44). It is a troponin found exclusively in the heart and not in other forms of muscle. Kidney function estimated by measurement of plasma creatinine concentration (Colorimetric kit, Biovision, Inc.) (FIG. 44). Satisfactory standard curves were constructed for each of the liver and kidney assays. Body weights were unaffected by the agent (results not shown). There was no evidence of liver, heart or kidney toxicity in male or female animals exposed for 2 weeks to as much as 100-fold the dose of P-bi-TAT that achieved maximal (3-10 mg/kg) anticancer therapeutic efficacy.

The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein. 

The invention claimed is:
 1. A method of synthesizing a composition, the method comprising: conjugating a non-biodegradable polymer to a thyroid antagonist using a linker; wherein the linker is covalently bound to the thyroid antagonist and the non-biodegradable polymer via a non-cleavable bond, wherein the linker comprises one of the following:

and wherein n₅=1-5, and A=CH or N, with at least one A=N.
 2. The method of claim 1, wherein the thyroid antagonist is selected from the group consisting of tetraiodothyroacetic acid (tetrac), triiodothyroacetic acid (triac) and derivatives thereof.
 3. The method of claim 1, wherein the non-biodegradable polymer is selected from the group consisting of polyethylene glycol (PEG), α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, alginic acid, chitosan and hyaluronic acid.
 4. The method of claim 1, wherein the composition is bi-functional and has two non-cleavable covalent bonds.
 5. The method of claim 1, wherein the composition is tetra-functional and has two non-cleavable covalent bonds.
 6. A method of synthesizing a thyroid antagonist composition having a non-cleavable covalent bond, the method comprising: providing a polymer; tosylating the polymer to form tosylated-polymer; reacting the tosylated-polymer with thyroid antagonist to form the thyroid antagonist composition having the non-cleavable covalent bond.
 7. The method of claim 6, wherein the thyroid antagonist composition having the non-cleavable covalent bond is bi-functional and has two non-cleavable covalent bonds; wherein the polymer is tosylated to form bi-tosylate-polymer; and wherein the bi-tosylated-polymer is reacted with thyroid antagonist to form the bi-functional thyroid antagonist composition having two non-cleavable covalent bonds.
 8. The method of claim 6, wherein the thyroid antagonist composition having the non-cleavable covalent bond is tetra-functional and has four non-cleavable covalent bonds; wherein the polymer is a tetra-polymer; wherein the tetra-polymer is tosylated to form tetra-tosylated-polymer; wherein the tetra-tosylated-polymer is reacted with thyroid antagonist to form the tetra-functional thyroid antagonist composition having four non-cleavable covalent bonds.
 9. The method of claim 6, wherein the thyroid antagonist is one of monoamino tetrac, a monoamino tetrac derivative, diamino tetrac, and a diamino tetrac derivative.
 10. The method of claim 6, wherein the thyroid antagonist is one of propargyl tetrac and a propargyl tetrac derivative, further wherein the step of reacting the tosylated-polymer with the thyroid antagonist comprises first reacting the tosylated-polymer with azide containing compound to form an azido-polymer compound and then reacting the azido-polymer compound with thyroid antagonist to form the thyroid antagonist composition having the non-cleavable bond.
 11. The method of claim 6, wherein the polymer is PEG and the method comprises: providing PEG; tosylating the PEG to form tosylated PEG; reacting the tosylated PEG with thyroid antagonist to form the thyroid antagonist composition having the non-cleavable covalent bond.
 12. The method of claim 11, wherein the provided PEG is a monomethoxy PEG; wherein the monomethoxy PEG is tosylated to form a monotosylated PEG; and wherein the monotosylated PEG is reacted with thyroid antagonist to form the thyroid antagonist composition having the non-cleavable covalent bond.
 13. The method of claim 12, wherein the polymer is PEG; wherein the thyroid antagonist is one of propargyl tetrac and a propargyl tetrac derivative; further wherein the step of reacting the tosylated-PEG with the thyroid antagonist comprises first reacting the tosylated-PEG with azide containing compound to form an azido-PEG compound and then reacting the azido-PEG compound with thyroid antagonist to form the thyroid antagonist composition having the non-cleavable bond.
 14. The method of claim 7, wherein the polymer is PEG; wherein the PEG is tosylated to form bi-tosylated PEG; and wherein the bi-tosylated PEG is reacted with thyroid antagonist to form the bi-functional thyroid antagonist composition having two non-cleavable covalent bonds.
 15. The method of claim 14, wherein the thyroid antagonist is one of propargyl tetrac and a propargyl tetrac derivative; further wherein the step of reacting the bi-tosylated PEG with the thyroid antagonist comprises first reacting the bi-tosylated PEG with azide containing compound to form a bi-azido-PEG compound and then reacting the bi-azido-PEG compound with thyroid antagonist to form the bi-functional thyroid antagonist composition having two non-cleavable covalent bonds.
 16. The method of claim 8, wherein the polymer is PEG; wherein the provided PEG is a tetra-PEG; wherein the tetra-PEG is tosylated to form tetra-tosylated PEG; wherein the tetra-tosylated PEG is reacted with thyroid antagonist to form the tetra-functional thyroid antagonist composition having four non-cleavable covalent bonds.
 17. The method of claim 16, wherein the thyroid antagonist is one of propargyl tetrac and a propargyl tetrac derivative; further wherein the step of reacting the tetra-tosylated PEG with the thyroid antagonist comprises first reacting the tetra-tosylated PEG with azide containing compound to form a tetra-azido-PEG compound and then reacting the tetra-azido-PEG compound with thyroid antagonist to form the tetra-functional thyroid antagonist composition having four non-cleavable covalent bonds.
 18. The method of claim 6, wherein the polymer is cyclodextrin, and the method comprises: providing a cyclodextrin polymer; tosylating the cyclodextrin polymer to form tosylated-cyclodextrin; reacting the tosylated-cyclodextrin with thyroid antagonist to form the thyroid antagonist composition having the non-cleavable covalent bond.
 19. The method of claim 6, wherein the polymer is cyclodextrin, and wherein the thyroid antagonist composition having the non-cleavable covalent bond is one of: a) bi-functional and has two non-cleavable covalent bonds; and b) tetra-functional and has four non-cleavable covalent bonds. 